This invention relates in general to measuring instruments and more particularly to a hand gauge for measuring loft and lie angles of golf clubs.
Fitting golf clubs to an individual golfer includes the consideration of several factors such as grip size, shaft length, swing weight and, of particular importance, loft and lie angular relationships of the golf clubs.
The loft angle of a golf club is the angle between a ball striking face of a club head and a plane that includes the golf club shaft axis and is disposed parallel to the lower edge of the face of the club head. Golf clubs having small loft angles are used for low trajectory-long flight golf shots, and golf clubs with large loft angles are for higher trajectory-shorter flight golf shots. The particular loft angle for each club in a set of golf clubs is not regulated by any standards or non-variable factors. Instead, the loft angles are normally predetermined by the designer of the clubs to achieve the desired performance characteristics for each club. During manufacture (and subsequent adjustments if accomplished) the loft angles of the clubs are checked and adjusted by bending the clubs as needed to bring them into conformity with the manufacturers predetermined angular values or to satisfy special requests that a golfer may make.
The lie angle is the angle between the shaft axis and a line tangent to the center point on the sole of the club head. If the lie angle is too small for a particular golfer, the club head will be angled upwardly as it impacts a golf ball, and the flight of the golf ball will be toward the left of the intended flight path. Similarly, if the lie angle is too large for a particular golfer, the club head will be angled downwardly as it impacts a golf ball and the flight of the golf ball will be toward the right of the intended flight path. The correct lie angle for an individual golfer is ideally determined by a trained fitting specialist, such as a PGA professional, who watches the golfers swing and can determine the correct lie angle by observing, among other things, the flight of the golf ball.
With properly fitted golf clubs, an individual golfer should be able to achieve optimum performance and shot reliability in accordance with his or her skill level. However, golf clubs can accidently be knocked out of adjustment and/or the golfer""s swing characteristics can change. When this occurs, the golfer""s performance level will deteriorate and in many instances, the golfer will not realize that the golf clubs are at fault. Therefore the loft and lie angles of golf clubs should be periodically checked and adjustments made if needed.
When checking or making changes in the loft and lie angles of golf clubs either at the time of manufacture or during subsequent adjustments, the clubs are usually placed one at a time in a special holding fixture that is part of a bench mounted measuring and adjustment mechanism. Such mechanisms usually make accurate measurements and provide visual indications of the loft and lie angles of the club being held in the fixture. With the club still in the holding fixture, special tools are used to bend the club head into the desired angular relationships. However, such bench mounted measuring and adjustment mechanisms cannot be considered portable and only manufacturing or large well-equipped golf shops can justify the cost or dedicate the space required by these mechanisms.
U.S. Pat. No. 4,934,706 issued to Marshall on Jun. 19, 1990 discloses a device which is described as a training aid rather than a gauge for measuring the angular relationships of golf clubs. The device is for mounting on a golf club shaft adjacent the grip and uses two bubble levels to indicate the lie angle and vertical disposition of the golf club as is being held in the address position by a golfer.
U.S. Pat. No. 5,421,098 issued to Muldoon on Jun. 6, 1995 discloses a device similar to the Marshall structure discussed above. The device is mounted part way up on the golf club shaft and employs two bubble levels to indicate the loft and lie angles preferred by the golfer while holding the golf club in the address position.
Both of these prior art devices require that a golfer be holding the golf club in the address position and they use the bubble levels to indicate the position in which the club is being held. These devices measure the loft and lie angles at which the golfer is holding the club rather than the actual angular relationships of the golf clubs. Therefore, a need exists for a new gauge for measuring the loft and lie angles of golf clubs.
In accordance with the present invention, a gauge for measuring loft and lie angles of golf clubs is disclosed. The gauge includes a body having a handle in which a rod is mounted for rotational and axial movements relative to the body. A clamp for gripping a hosel of a golf club head is carried on an inner end of the rod. A first indicia assembly is mounted on the body and on the rod to provide a visual indication of the angular relationship between the body and the rod. The angular relationship between the rod and the body, as indicated by the first indicia assembly, is the lie angle of the golf club being measured.
A face engaging member in the form of a plate is carried on the gauge body and is rotationally and axially movable therewith relative to the rod. The plate is also pivotally movable relative to the body into engagement with a ball striking face of the golf club to be measured. A second indicia assembly is mounted on the plate and on the gauge body to provide a visual indication of the pivotal position of the plate. The pivotal position of the plate, as indicated by the second indicia assembly, is the loft angle of the golf club being measured.
To measure the loft and lie angles of a golf club, the gauge is attached to the golf club by the clamp which grips the hosel of the club head. This places the handle of the gauge body, and the rod carried therein, in a normally extending position relative to the hosel axis and the shaft axis of the golf club. The clamp is configured so that the rod and the entire gauge can be rotated about the shaft axis of the golf club. Such movement is employed to bring the face of the golf club head into parallel relationship with the pivot axis of the face engaging plate. Axial movement of the handle along the axis of the rod is used to move the gauge body toward the golf club to bring the plate into engagement with the face of the club head. The plate is then pivotably moved about its pivot axis to bring it into contiguous engagement with the face of the club, and when so positioned, the second indicia assembly will display the loft angle of the golf club.
As is customary, grooves are provided on the faces of golf club heads and they are parallel to a line that is tangent to a center point on the sole of the club head. Rotational movements of the gauge body about the rod axis are used to bring an edge of the plate into parallel alignment with those grooves. Such movements will bring a laterally extending portion of the gauge body into precise parallel alignment with this tangent line. The clamp carried on the rod holds the rod so that a portion of the first indicia assembly mounted thereon will be indicative of the relative position of the golf club shaft axis. With the gauge body being in alignment with the tangent line and the rod being indicative of the shaft axis position, the angular relationship between the rod and the body, as indicated by the first indicia assembly, will be the lie angle of the golf club.